DutchManDann

I have a 1998 GT convertible, it has a 2001 GT Engine in it. The engine has around 40,000 miles on it and was rebuilt in 2003 by Ford.

I am just wondering if anyone can give me an estimate of what my horsepower would be at the flywheel with my current mods:

-Offroad H-pipe
-"XLerator" exhaust (I have heard these are most like Flowmasters on a budget)
-K&N drop in air filter w/ removed air silencer

And while I am at it I might as well ask how I can increase lower end power and throttle response. I am thinking a BAMA tuner once I get some money, and then a throttle body and plenum. I might do gears instead of the t/b and plenum though (3.55s or 3.73s).


Thanks,
DMD

98mustangkidd

So you've swapped the engine, correct? Usually when you do the PI swap on our cars it's the H/C/I that get swapped because you get a larger bump in compression. I'm not really sure about the power gains because I'm going through the process right now, but just the H/C/I, I've heard like 50 to 60 HP... I'm hoping. as for low end torque, get handheld tuner and if your going to go with F/I down the road go with 3.73s but if your staying N/A I'd go straight to 4.10s... You'll see the greatest low end gains out of gears other than F/I. GoodLuck!

DutchManDann

Yeah I swapped the entire engine, I also created a wiring harness that let me keep the COPs from the new engine.

And as far as gears go, how hard is it to put them in? And how badly would 3.55s or 3.73 effect my highway driving? I did the whole engine swap myself,and I would say I am good at mechanical things.

Based on what you said I will probably start with the tuner. TheBAMA tuner from American Muscle looks the best to me.

Rockwell28

I only lost 2-3 mpg highway with my 3:73s so with those two choices it want affect it much but that depends on what you consider much on the maximum end me losing 3mpg from 15.7 gallons means I lost 47.1 gallons from a complete tank on the highway.

98mustangkidd

I had mine installed by my mechanic so I helped him out also. They weren't too hard, a lift makes it a lot easier, its getting the back lash right is what's going to be difficult if you dont have the right tools.. I have 4.10s and saw almost no difference in highway and actually gained in city.

Rockwell28

some will sat that "there is no loss on highway mileage" but with simple math of spinning higher rpms on the highway at a given cruizing speed there will be an obvious loss some ppl just dont care or pay attention to it. city should stay about the same or even better but with higher cruizing speed rpms with a gear change there Will be a loss on the highway. If there wasnt these cars would come from the factory with 4:88s lol.

jeh4269

The 98's had 225 hp at the flywheel and the 99-04's had 260 hp at the flywheel.Most guys do the H/C/I swap and use the 96-98 bottom end bc they have a slightly higher compression than the 99 -04's.So you gained 30-35 hp with the PI motor.I'm not sure how much your exhaust will add.

DutchManDann

Yeah im going to aim for 3.55s or 3.73s because in the distant future I plan on supercharging and building the engine, but that's not going to happen for a long time.

As far as the tuner goes, will it widen the cars power band? I was doing some pulls on the highway and it seems like the car pulls hard after 2800 -3000rpms

uberstang1

Definatly go with the 3.73s if thats the two choices.

DutchManDann

Between those two choices, what will the difference be on the highway? And also how will my gas mileage be affected?

Knowing myself, I'll probably end up going with 3.73s (might as well just go all out) but 3.55s are still an option